1. Field of the Invention
The invention relates to an image forming apparatus in which a cartridge storage means for saving intrinsic information including information on the life of a developer cartridge is provided in the developer cartridge constructed to be detachably mountable into an apparatus main body, and a storage controlling method for information on an improper detachment of the developer cartridge to be written in the cartridge storage means.
2. Description of the Related Art
In printers, copiers, facsimile apparatuses and like image forming apparatuses for forming images using toner, a toner container is so constructed into a developer cartridge as to be detachably mountable into an apparatus main body, so that user can easily replenish the toner himself (for example, see Japanese Unexamined Patent Publication No. 2002-23595). In an apparatus disclosed in Japanese Unexamined Patent Publication No. 2002-23595, a developer is moved to a specified detachment position when user turns a switch on during a non-recording operation.
Further, some of such constructions in which the developer cartridge is detachably mountable have been known to provide a cartridge memory formed of, e.g. a nonvolatile memory for saving intrinsic information of the developer cartridge such as information on the life of the developer cartridge including an amount of toner contained in the developer cartridge, the color of the toner, and the production date of the developer cartridge (for example, see Japanese Unexamined Patent Publications Nos. 2002-341706, 2001-290400). An apparatus disclosed in Japanese Unexamined Patent Publication No. 2002-341706 is constructed such that a main-body controller reads and writes information from and in the cartridge memory with a developer-cartridge side connector electrically connected with the cartridge memory and a main-body side connector electrically connected with the main-body controller connected with each other. An apparatus disclosed in Japanese Unexamined Patent Publication No. 2001-290400 is constructed such that information is read and written from and in the cartridge memory in a noncontacting manner via an antenna.
In the above-mentioned conventional apparatuses, the reading and writing from and in the cartridge memory are discontinuously performed at specified timings such as the detachment timing of the developer cartridge, for example, in view of how often rewriting can be made in a nonvolatile memory until the life of the nonvolatile memory ends, how often the connectors can be connected to connect the apparatus main body and the developer cartridge until the lives of the connectors end, and how often an actuator for moving the connectors toward and away from each other can be driven until the life thereof ends. Accordingly, information on the life saved in the cartridge memory does not always agree with the latest data.
For example, if the reading and writing from and in the cartridge memory are performed only when the developer cartridge is detached, the information on the life saved in the cartridge memory of the mounted developer cartridge does not agree with the latest data until the developer cartridge is detached from the apparatus main body.
Since the developer cartridge is so constructed as to be exchangeable by the user himself as described above, it may be used as follows, for example, upon mass printing. Specifically, the developer cartridge being used is temporarily detached and stored, and, after a new developer cartridge is mounted and mass printing is carried out, the new developer cartridge is detached and the old one is mounted again. In the case of using the developer cartridge mentioned above, unless the latest data on the life is written in the cartridge memory so that the information on the life agrees with the latest data before the developer cartridge is detached, the information on the life read from the cartridge memory when the developer cartridge is mounted again is incorrect. Therefore, the life of the developer cartridge cannot be precisely administered.
However, depending on the construction of the image forming apparatus, the developer cartridge can be improperly detached by a user before the information in the cartridge memory is updated.
For example, in such a construction in which a reading/writing position from/in the cartridge memory differs from the detachment position for the developer cartridge and the developer cartridge passes its detachment position while being moved to the reading/writing position from/in the cartridge memory, the user may inadvertently detach the developer cartridge when the developer cartridge passes the detachment position.
Further, if the developer cartridge accidentally stops at the detachment position when power supply is inadvertently shut off during the operation, for example, due to a power failure or the maloperation of a power switch by the user, the developer cartridge may be detached by the user.
Upon such an improper detachment, the information on the life in the cartridge memory is not updated to the latest data. Thus, the life cannot be precisely administered even if the saved content of the cartridge memory is read when the detached developer cartridge is used again later.